Exhaust-muffler for internal-combustion motors



P. H. LE'SSER.

EXHAUST MUFFLER FOR INTERNAL COMBUSTION MOTORS. APPLICATION FILED MAR. 22. 1919. RENEWED JAN. 19, I921.

"1,370,45 Patgnted Mar. 1,1921.

ammo o PHIL/P H. LESSER UNITED STATES PATENT OFFICE.

PHILIP H. LESSER, OF FBANKIJIN, PENN SYLVANIA.

Specification of Letters Patent.

Patented Mar. 1, 1921.

Application filed March 22, 1919, Serial No. 284,259. Renewed January 19, 1921. Serial No. 43?,528.

To all whom it may concern Be it know'n that I, PHILIP H. Lassen, a citizen of the United States, residing at Franklin, in the county of Venango and State of Pennsylvania, have invented certain new and useful Improvements in Exhaust-Mufilers for Internal-Combustion Motors, of which the following is a specification.

The object and construction of this invention are herein .set forth with sufficient clearness to enable those skilled in the respective arts to which its construction and use relate, to make and use the same.

The object of this invention is, to provide an eflicient silencer or mufller for the exhaust of an internal combustion motor, whereby the sound caused by the escaping gases from the combustion chamber of an internal com bustion motor, at the end of the power stroke, will be nullified.

One form of construction whereby I at tain said object, is clearly shown in the accompanying drawings, which form a part hereof, the respective figures of which are as follows:

Figure 1 is a central, longitudinal section of my improved muffler.

Fig. 2 is an elevation of same.

Fi 3 is a transverse section on line 111- II of Fig. 1.

As illustrated in said drawings, myimproved mufiler comprises a tubular structure, formed into a' series of expansion chambers, 1, 1, 1, which have means of intercommunication through axially-alined, restricted openings 2; said chambers preferably have a shape similar to that of a frustum of..a cone. 1

Suitable pipe connections, 3, 4, are provided at the respective ends of said chambered structure. so that the mufller may be easily connected tov the exhaust outlet, or interposed in the exhaust piping of an internal combustion motor.

The mufiler is referably so connected that the exhaust will pass through the same in the direction-indicated by the arrows in Fig. 1, as this way of connecting has been found to give the best results in actual practice; the mufller may, however, be connected with e1ther end tothe engine, and give satisfactory results in either case.

For the purpose of imparting a symmetrical and neat appearance to the mufller, said chambered structure is inclosed within a cylindrical shell or casing 5, which may be attached to said body in any suitable way, as by screws, 6.

Saidcasing performs a further function of mufliing the noise caused by the rush of the exhaust gases through the expansion chamber. The sound produced by this passage of the exhaust through the expansion chamber, resembles that caused .by pouring fine shot into a sheet iron vessel, and the casing muiiles this noise so it is scarcely perceptible. In order to most effectually accomplish this result, I have discovered that said casing must be attached to the expansion chamber in such a way that there may be a certain amount of free relative move ment between these two members, thus pro-. v

viding for a difference in expansion, caused by the expansion chamber becoming more highly heated than the casing, which is due to the direct impingement of the exhaust gases upon the inner walls of said expansion chamber. This result is attained by attaching said two members together at one point only, as by the screws 6; in this way, no tension or compression is exerted by one member upon the other, they are each free to expand and contract independently, and for this reason vibration, and the tendency of these members to transmit sound, is reduced to a minimum.

A further result attained by the provision of said casing 6 is the formation of an annular chamber or dead-air space 7 around each compartment 1 of the expansion chamber, and these spaces 7 also materially assist in muflling the sound produced by the passage of the exhaust through said expansion chamber.

I claim: 1 I A mufiler for internal combustion engines comprising, in combination, an expansion Q ere-we chamber consisting of a unitary structure formed into a plurality oi. truncated-conical compartments having axially-Mined, intercommunicating openings, the junctionel oints of said; compartments at said openlngs being flush, the metal about the openings at the respective ends of said cham her being formed into pipe connections; and a tubular casing for said expansion chamber attached to the periphery thereof at one 10 end, as and for the purgcse set forth.

' In testimony whereof afiix my signature lIl presence of two witnesses.

PHILIP H. LESSER.

Vitnesses:

RALPH L. CARR, WM. B. GRIFFEN. 

